Brain Surgery-Aneurysms

Aneurysms are defects in the wall of an artery. Aneurysms are like small balloons that develop along an artery, usually at the division of an artery into two smaller branches. Over time, aneurysms grow, and occasionally rupture. When an aneurysm ruptures, bleeding occurs in the brain. We call this a “sub-arachnoid hemorrhage.” This type of bleeding can be fatal. In fact, it is estimated that one-half of the people who have ruptured aneurysms die before they even arrive at the hospital. Once under the care of a surgeon, there remains a risk of a second bleeding episode. The re-bleeding of an aneurysm is also fatal 50% of the time, even when it occurs in the hospital. Ruptured aneurysms are treated by either a craniotomy and clipping of the aneurysm, or by endovascular therapy. Unruptured aneurysms may be treated with the same techniques. Recent research suggests that there may not be an advantage to treating some small aneurysms.

Arteriovenous malformations are also called AVMs, are a second type of blood vessel abnormality within the brain. AVMs are made of abnormal connections between arteries and veins. Blood flows very quickly through these abnormal vessels, by-passing the normal capillaries within the brain. The AVM has very thin walls and is prone to bleed. Patients with AVMs may suffer from repeated stroke symptoms with each episode of bleeding as well as seizures and hydrocephalus. Like aneurysms, bleeding within the brain can be fatal.

AVMs can be treated with surgery, endovascular therapy, or Gamma Knife radiosurgery. With traditional surgery, the skull is opened, and the AVM is removed, along with a portion of the surrounding brain. With the Gamma Knife, the abnormal blood vessels are targeted with radiation. Over time, the blood vessels close, destroying the AVM.